Life Sciences Commons^™

Factors That Influence Small Mammal Long Bone Morphology: An Analysis Of The Femora, Tibiae, And Humeri Of The Eastern Gray Squirrel (Sciurus Carolinensis), Tyler Everette Blake

Theses, Dissertations and Capstones

The goal of this study is to examine the effect of urbanization and latitude on bone morphology, specifically limb length and bone density among gray squirrels endemic to the eastern United States. This study’s hypotheses are as follows: gray squirrels occupying lower latitudes will have larger body sizes and longer limbs relative to body size than those at higher latitudes following Bergmann’s and Allen’s rules. Further, squirrels in urban habitats will have greater bone density than those in rural habitats. Results show moderate correlation between body mass and respective proxies and latitude following Bergmann’s rule. Weak correlations were found between …

New Synonyms And Records Of Costa Rican And Panamanian Dung Beetles (Coleoptera: Scarabaeidae: Scarabaeinae), Ángel Solis, Bert Kohlmann

Insecta Mundi

To better understand the dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) biodiversity of Costa Rica and Panama, new synonyms, records, distributions, and updates are presented. This paper analyzes the distribution and taxonomy of Phanaeus olsoufieffi Balthasar, 1939 in Panama and establishes the following new subjective synonym: Phanaeus panamensis Moctezuma and Halffter, 2021 = Phanaeus olsoufieffi Balthasar, 1939. Color morphs of Phanaeus pyrois Bates, 1887 in Costa Rica are analyzed. The Costa Rican distribution of Onthophagus bidentatus Drapiez, 1819 and O. marginicollis Harold, 1880 is stud­ied. Onthophagus bidentatus is recorded for Costa Rica for the first time. A population analysis of barcode mtDNA, …

Quantitative Silviculture Of Northern Conifers, David G. Ray

Electronic Theses and Dissertations

Quantitative tools used to guide the management of important northern conifer species require updating and refinement to address changes in the contemporary resource and evolving objectives of ownership. This work builds on an extensive body of knowledge about stand density management and innovates some new approaches. In sum, the three chapters presented herein: 1) seek to strengthen and more fully articulate arguments for adopting relative density as a primary metric of stand density assessment, 2) quantify minimum stand densities to achieve full site occupancy and argue for more parity with treatment of maximum stand density, and 3) present an empirically …

Reproductive Traits And Change In Body Shape Of Neonates In The Oak Forest Skink, Plestiodon Lynxe, Manuel Feria-Ortiz, Uri Omar García-Vázquez, Carlos Joaquín Pavón-Vázquez, Adrián Nieto-Montes De Oca

Publications and Research

Reproductive traits are critically important for understanding how organisms adapt to their respective environments. In this study, we provide information on relative litter mass (RLM) and other litter and neonate related characters of nine female Plestiodon lynxe captured in the field. We also recorded seven body dimensions in 16 neonates and 15 two-month juveniles, and on the basis of these dimensions we compared the body shape of these two age classes to detect changes in the proportions of body parts. The average litter size (4.55) is larger than that found in other viviparous species of Plestiodon, but smaller than …

Scaling And Ecological Relationships In The Visual Ecology Of Sharks, Brianna Hall

Electronic Theses and Dissertations

Adaptations of visual systems, such as acuity, sensitivity, and eye size can be used to infer the relative importance of vision to an organism. The high metabolic cost of visual system development and maintenance suggests that large relative eye size (as it relates to body length) may have a significant ecological or evolutionary role. Elasmobranchs are morphologically diverse and inhabit a wide range of marine and freshwater niches. As energetic and ecological demands shift over time, several species occupy different predatory niches across their lifetime, yielding a large array of visual habitats. Additionally, eye size changes with body length allometrically, …

Body Condition Helps To Explain Metabolic Rate Variation In Wolf Spiders, Stella F. Uiterwaal, John P. Delong

School of Biological Sciences: Faculty Publications

1. Metabolism is the fundamental process that powers life. Understanding what drives metabolism is therefore critical to our understanding of the ecology and behavior of organisms in nature.

2. Metabolic rate generally scales with body size according to a power law. However, considerable unexplained variation in metabolic rate remains after accounting for body mass with scaling functions.

3. We measured resting metabolic rates (oxygen consumption) of 227 field-caught wolf spiders. Then, we tested for effects of body mass, species, and body condition on metabolic rate.

4. Metabolic rate scales with body mass to the 0.85 power in these wolf spiders, …

Polar Gigantism And Sea Spiders: A Study Of Respiratory Scaling, Steven Joseph Lane

Graduate Student Theses, Dissertations, & Professional Papers

All animals must breathe to survive. The types of primary respiratory structures vary across the metazoa, and the overall size and components of these structures scale with body size. The scaling of respiratory structures has been well studied in vertebrate lungs and gills, but very few, if any studies, have looked at it in terms of cutaneous gas exchange, the process where oxygen moves across the outer integument via diffusion. My dissertation has sought to fill this gap in knowledge by studying animals that use cutaneous respiration, and my work has determined both how the components of their respiratory surfaces …

Analyzing Pterosaur Ontogeny And Sexual Dimorphism With Multivariate Allometry, Erick Charles Anderson

Theses, Dissertations and Capstones

The relationships of pterosaurs have been previously inferred from observed traits, depositional environments, and phylogenetic associations. A great deal of research has begun to analyze pterosaur ontogeny, mass estimates, wing dynamics, and sexual dimorphism in the last two decades. The latter has received the least attention because of the large data set required for statistical analyses. Analyzing pterosaurs using osteological measurements will reveal different aspects of size and shape variation in Pterosauria (in place of character states) and sexual dimorphism when present. Some of these variations, not easily recognized visually, will be observed using multivariate allometry methods including Principle Component …

Morphological Response In Sister Taxa Of Woodrats (Genus: Neotoma) Across A Zone Of Secondary Contact, Michaela M. Koenig

Master's Theses

This study focuses on a secondary contact zone between two sister species of woodrat, Neotoma fuscipes (dusky-footed woodrat) and N. macrotis (big-eared woodrat). Along the Nacimiento River, on the border of southern Monterey and northern San Luis Obispo counties, the ranges of these sister species of woodrats meet and overlap forming a secondary contact zone. The zone of secondary contact is estimated to include a 500-meter (~1,650 linear feet) portion of the Nacimiento River riparian corridor.

This research examines quantifiable morphological change that is likely associated with heightened inter-specific competition within the contact zone. When in sympatry the sister species …

Evolutionary Pressures On Primate Intertemporal Choice, Jeffrey R. Stevens

Department of Psychology: Faculty Publications

From finding food to choosing mates, animals must make intertemporal choices that involve fitness benefits available at different times. Species vary dramatically in their willingness to wait for delayed rewards. Why does this variation across species exist? An adaptive approach to intertemporal choice suggests that time preferences should reflect the temporal problems faced in a species' environment. Here, I use phylogenetic regression to test whether allometric factors (relating to body size), relative brain size, and social group size predict how long 13 primate species will wait in laboratory intertemporal choice tasks. Controlling for phylogeny, a composite allometric factor that includes …

A Comparison Of Relative Ear Length Between Two Neighboring Populations Of Peromyscus Maniculatus, Joshua S. Willems

Biological Sciences

This study attempts to determine if a significant difference in relative ear length exists between two neighboring populations of Peromyscus maniculatus on the central coast of California. Data was collected from individuals trapped at two plots in the Guadalupe-Nipomo Dunes National Wildlife Refuge and two plots near Black Lake, under the supervision of Francis X. Villablanca, Ph. D. of California Polytechnic State University, San Luis Obispo. A total of 98 individuals were captured over the course of three nights of trapping. A regression analysis was performed comparing the ear lengths of each population relative to body size. The analysis of …

Plasticity Of Chasmogamous And Cleistogamous Reproductive Allocation In Grasses, Gregory P. Cheplick

Aliso: A Journal of Systematic and Floristic Botany

Cleistogamy is more common in grasses than in any other angiosperm family. Both self-fertilized cleistogamous (CL) spikelets and open-pollinated chasmogamous (CH) spikelets are typically produced. Relative allocation to CL and CH varies among species and populations, and is influenced by ontogeny and environment. The balance between reproductive modes can be expressed as a CH/CL ratio. This ratio is very plastic, and stressful conditions can result in values Amphicarpum purshii, an annual with subterranean CL spikelets, CH/CL declined as density increased because CH decreased more than CL as size was reduced by intraspecific competition. In the shade-tolerant annual Microstegium vimineum, …

Metabolic Rate Models And The Substitutability Of Predator Populations, David R. Chalcraft, William J. Resetarits Jr.

Biological Sciences Faculty Publications

1. Much of the debate surrounding the consequences of biodiversity loss centres around the issue of whether different species are functionally similar in their effects on ecological processes. In this study, we examined whether populations consisting of smaller, more abundant individuals are functionally similar to populations of the same species with larger, fewer individuals.
2. We manipulated the biomass and density of banded sunfish (Enneacanthus obesus) and measured their impact on populations of Southern leopard frog (Rana sphenocephala) larvae. We also evaluated the ability of models relating metabolic rate to body size to predict the relative …